Closed mtn account/customer service bad

my wife has just closed her Mtn account at Campus Square but the service consultant says she must also send a email to Mtn to confirm the closure. Why must she do there jobs for them. they are lazy.She is trying to call Mtn for 2 days but gets cut off. If any account is sent to us for payment we will sue Mtn for bad service delivery. Her contract is finished so she closed her account. Her no is ***. We want this matter handled with urgency. Mtn is quick to bill clients but have no customer service when clients request account closures. My wife can be contacted on ***